An instrument enclosure apparatus typically comprises a number of computer hardware devices such as a motherboard, Printed Circuit Board (PCB), transformer, fan, display panel and processor. The instrument enclosure apparatus protects the hardware from damage that may arise from shock, vibration or external abrasion and provides a convenient package enabling the hardware to be portable and suitable for bench-top use or rack mounting. The instrument enclosure apparatus may also comprise means to shield the hardware from electromagnetic interference (EMI) and electrostatic discharge (ESD) generated by hardware external to the instrument enclosure apparatus and also from the enclosed hardware itself.
A known approach in the manufacture of an instrument enclosure apparatus uses a combination of punched-sheet-steel enclosure parts together with one or more plastic mouldings. The enclosure parts are shaped before assembly of the instrument enclosure apparatus using a suite of hard tools; a manufacturing process known as a ‘hard-tooling’. Hard-tooling typically uses a single hit power-press tool designed to produce a fixed configuration of the enclosure parts. In order to achieve some flexibility and therefore enable more than one design to be produced using the enclosure parts, the manufacturing process of the enclosure parts is split into a number of discrete stages, for example: pierce, blank, fold-stage one, fold-stage two. To further increase flexibility, additional movable elements such as punch and die clusters may be used.
The instrument enclosure apparatus is typically designed to provide a cooling regime for the particular configuration of hardware it is to accommodate when manufacture is complete. The cooling regime is necessary in order to prevent damage or inefficient operation of the hardware through overheating. The cooling requirements of a particular instrument enclosure apparatus can be met through the distribution of vents along the sidewalls of the instrument enclosure apparatus and by employing active cooling methods such as a fan within the instrument enclosure apparatus, or by employing passive cooling methods where thermal convection is used to drive air circulation within the instrument enclosure apparatus. Both active and passive cooling methods aim to expel warm air through the vents and replace the warm air with cooler air drawn from the exterior of the instrument enclosure apparatus.
The above manufacturing approach is disadvantageous because such suites of hard tools are expensive and changing the width or length of the instrument enclosure apparatus normally requires a new suite of expensive tools to be designed and used to create the new instrument enclosure apparatus. Furthermore, should a new configuration of hardware be inserted within the instrument enclosure apparatus, the cooling regime designed for the earlier hardware configuration may not be suitable for the new hardware configuration. Following manufacture, the above described instrument enclosure apparatus is not flexible in design due to the fixed configuration of the enclosure parts, and therefore, in order to accommodate a new cooling regime, a new instrument enclosure apparatus is typically manufactured.
Alternatively, an instrument enclosure apparatus such as an injection moulded, plastic clamshell can be manufactured. Such plastic clamshells are normally cheaper to manufacture than the steel instrument enclosure apparatuses mentioned above. A clamshell is a particular design of instrument enclosure apparatus comprising a base portion and a lid portion. An assembly of a clamshell instrument enclosure apparatus comprises insertion of the hardware within the base portion, followed by fixing the lid portion to the base portion to complete the assembly process. Such an assembly process is known in the art as ‘top-down’ assembly. The disadvantage of present injection moulded clamshell enclosure apparatus is that each particular clamshell instrument enclosure apparatus is designed for a single product and is designed to support a particular cooling regime dependent upon the layout and/or type of hardware it is to accommodate when assembled. Therefore, a change in the configuration of the hardware and a consequent change in the cooling requirements of the clamshell instrument enclosure apparatus requires a replacement enclosure to be designed and manufactured. Known clamshell instrument enclosure apparatus designs are therefore not well suited for reuse or to accommodate a change in the layout and/or type of hardware they comprise during their lifetime.